Yes, if the co-ax out you refer to is a digital out. the player needs a digital output. Then you need a properly terminated digital cable and analog outputs from the DAc to a pre, rcvr, or integrated, and you are good to go.

The posters above are correct, but you're not quite done yet. You also need to go into the setup menu of the DVD player and set the digital output to be stereo. You'll see that option as PCM, LPCM or something of that nature. It can't be bitstream. That way, a movie or concert DVD in surround will output a stereo digital signal that the DAC3 can process. If the DAC3 receives a bitstream surround digital signal it will mute the output since it cannot handle these types of formats.

Generally, if the CDP allows for digital coax out, then the upgrade will be significant. I send my iPod digital out via a Wadia 170i interface into my Playback Designs MPS-5 with truly amazing quality. The DAC3 will generally be a major improvement over any base level CDP's DAC.